Display the amount of free memory in the Java Virtual Machine. : Runtime System « Development « Java Tutorial

1. Java Tutorial
2. Development
3. Runtime System

import java.text.DecimalFormat;

public class Main {
  public static void main(String[] args) {
    DecimalFormat df = new DecimalFormat("0.00");

    long freeMem = Runtime.getRuntime().freeMemory();
    System.out.println(df.format(freeMem / 1000000F) + " MB");
  }
}